CN112818523A - Medium-low voltage direct current metering point selection method based on fuzzy evaluation model - Google Patents
Medium-low voltage direct current metering point selection method based on fuzzy evaluation model Download PDFInfo
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Abstract
The invention discloses a medium and low voltage direct current metering point selection method based on a fuzzy evaluation model, and belongs to the technical field of medium and low voltage direct current metering. According to the selection method of the middle and low voltage direct current metering points based on the fuzzy evaluation model, the proper metering points are selected by evaluating the plurality of alternative metering points through the fuzzy comprehensive evaluation model; which comprises the following steps: firstly, constructing a factor set U; secondly, constructing a comment set V; thirdly, constructing a weight set A; and fourthly, giving a judgment decision matrix for each metering point. According to the method, through continuous exploration and test, for a plurality of alternative metering points, a factor set, a comment set, a weight set and a judgment result matrix are constructed by using a fuzzy comprehensive evaluation model, and the final comment results of all schemes are compared to select a final metering point configuration scheme, so that the influence of subjective factors can be effectively reduced, the metering points can be selected more scientifically, reasonably and accurately, and the method is favorable for popularization.
Description
Technical Field
The invention relates to a selection method of a middle and low voltage direct current metering point based on a fuzzy evaluation model, and belongs to the technical field of middle and low voltage direct current metering.
Background
The development of the direct-current power grid technology puts new requirements on direct-current measurement. At present, the current national standard and industrial standard of China integrally stipulate the setting of a power grid metering point. However, in a medium-low voltage direct current distribution network, a large number of distributed power supplies and direct current loads are connected, so that alternative solutions of measuring points are increased. In addition, with the gradual arrival of electricity transformation steps, the electric power company not only needs to ensure the reliability and accuracy of the system, but also needs to consider the economy in engineering design, so that many factors need to be considered, and screening is carried out only by subjectivity, so that many uncertain factors exist, the selection scheme has great unscientility and randomness, and a scientific, reasonable and accurate selection scheme is lacked.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a medium and low voltage direct current metering point selection method based on a fuzzy evaluation model, which is characterized in that a final metering point configuration scheme is selected by comparing final evaluation results of all schemes through constructing a factor set, an evaluation set, a weight set and an evaluation result matrix, so that the influence of subjective factors can be effectively reduced, the metering points are more scientifically, reasonably and accurately selected, and the method is favorable for popularization.
In order to achieve the purpose, the technical scheme of the invention is as follows:
a selection method of middle and low voltage direct current metering points based on a fuzzy evaluation model,
evaluating the plurality of candidate metering points through a fuzzy comprehensive evaluation model to select a proper metering point;
which comprises the following steps:
firstly, constructing a factor set U; the set of factors U includes "accuracy U1"," economy u2", and" feasibility u3", i.e. U ═ U1，u2，u3}；
Secondly, constructing a comment set V;
the comment set V includes "good V1"," preferably v2"," acceptable v3"and" unacceptable v4", i.e. V ═ V1，v2，v3，v4}；
Thirdly, constructing a weight set A;
weight set a ═ a1，a2，a3Represents the system setting of each factor respectivelyCalculating the proportion occupied in the decision;
fourthly, according to the membership degree of the factor set to the comment set, a judgment decision matrix is given to each metering point
Row vector [ r ] of the evaluation decision matrixi1，ri2，ri3，ri4]Representing the degree of membership of the factor in the set of comments;
it should be noted that the sum of the row vectors of the evaluation matrix is 1, i.e. the sum of the row vectors of the evaluation matrix is 1
Fifthly, constructing a judgment result matrix B as A multiplied by R to obtain a judgment result matrix B as B1，b2，b3，b4]；
Four elements in the evaluation result matrix respectively correspond to the membership degree of the scheme in the evaluation set, and the maximum value B is taken as max B to serve as the final evaluation result of the scheme;
sixthly, selecting a final metering point configuration scheme by comparing final comment results of all schemes;
and when the comment results are the same, selecting the person with the highest membership degree.
According to the method, through continuous exploration and test, for a plurality of alternative metering points, a factor set, a comment set, a weight set and a judgment result matrix are constructed by using a fuzzy comprehensive evaluation model, and the final comment results of all schemes are compared to select a final metering point configuration scheme, so that the influence of subjective factors can be effectively reduced, the metering points can be selected more scientifically, reasonably and accurately, and the method is favorable for popularization.
As a preferable technical measure:
the first step, selecting a plurality of alternative metering points, wherein the metering points are selected mainly according to national standards GB/T33708-2017 and industry standards DL/T1484-2015 and DL/T448-2016, and each metering point is ensured to meet basic requirements; and generating a plurality of metering point configuration combination schemes as an alternative.
The method is based on a network topology structure of the direct-current power distribution network, considers the symmetry of the direct-current power distribution network and the distributed power grid-connected structure, starts from national standards and industrial standards, and applies a fuzzy comprehensive evaluation model. The accuracy, the economy and the feasibility of the setting of the metering points are comprehensively considered, and the optimal scheme can be screened out from the potential metering points which accord with the national standard and the industrial standard.
As a preferable technical measure:
thirdly, adjusting the weight set data according to actual requirements;
when the overall design of the system is more biased to economy, the value of a2 is larger;
the sum of the elements of the weight set is 1, i.e.
As a preferable technical measure:
and in the fourth step, the membership degree evaluation method comprises a statistical method and a membership function method.
The invention adopts a statistical method, namely, an operator scores the existing scheme according to experience by depending on a simulation result; and counting the scoring results to obtain the membership degree.
As a preferable technical measure:
for a two-stage photovoltaic grid-connected system with a direct-current load, 3 potential metering points are selected for site selection according to national standards and industrial standards, and three metering point combination schemes are provided:
in the first scheme, three metering points are selected completely;
selecting two metering points;
and a third scheme, selecting a metering point:
configuring an evaluation decision matrix and a weight set according to an empirical method;
the three schemes evaluate the decision matrix and weight set as follows:
scheme 1:
scheme 2:
scheme 3:
weight set A ═ 0.30.40.3-
The final evaluation result is:
scheme 1: b is1＝|0.35 0.19 0.39 0.07|
Scheme 2: b is2＝|0.16 0.47 0.30 0.07|
Scheme 3: b is3＝|0.22 0.42 0.33 0.06|。
In the scheme 1, the metering point is completely set, the actual inflow/outflow electric energy of each device is fully considered, the influence of line loss on metering is minimum, and therefore the accuracy is highest. But at the same time, a plurality of electric meters are installed, and the system cost is increased. In the installation feasibility, when the user side is involved, factors such as whether residents agree to power failure installation equipment or home construction and the like are often involved, and the installation difficulty is high. In the scheme 3, only power exchange between the grid-connected system and the main grid is considered, and the electricity consumption situation of the residential load side cannot be fully reflected. Therefore, the scheme 2 is most scientific and reasonable.
As a preferable technical measure:
the method for metering the medium-low voltage direct current metering points comprises the following steps:
collecting system operation information and metering electric energy;
reading the collected metering data and equipment alarm information, and storing the data;
processing the acquired data, analyzing the running state of the system and calculating the electric charge;
data processing includes, but is not limited to: flicker analysis, ripple analysis, tip, peak, valley and level analysis and system direct current power flow analysis; issuing a system operation instruction according to the data processing result, and transmitting the instruction to the control station through the server, thereby realizing electric energy management;
simulating the running state of the system, and giving a measurement result reference range of the key measurement point as a measurement result calibration standard; if the simulation result is larger than the reference range and no alarm information exists at the moment, sending information to a person in charge of the metering point where the simulation result is located, and informing the person to go to the position where the metering point is located to troubleshoot faults.
The invention measures the electric energy by acquiring the actual operation information of the system; meanwhile, the electric energy can be effectively managed and the metering result can be corrected according to the collected information, and the scheme is scientific, reasonable and accurate; the method can meet the requirements of scientific measurement of medium and low voltage direct current transmission systems of power grid companies and users.
Further, the simulation process in the fourth step specifically includes the following steps:
s1, logging in the system by a terminal manager;
s2, after logging in, the terminal manager inputs weather forecast conditions, load forecast conditions, direct current converter station control modes, system direct current bus voltage standard values and system direct current bus power standard values into the system;
s3, after data entry, running simulation to obtain a simulation result;
in the specific simulation process, a simscape power system toolbox in matlab/simulink software can be used for modeling according to the topological structure of the power distribution network through an existing component library in the toolbox, and then data in S2 is input to obtain a simulation result;
s4, comparing the simulation result with the measurement result of the given key measurement point;
if the simulation result is greatly different from the measurement result of the given key measurement point and no alarm information exists at the moment, the electric energy management layer sends information to the responsible personnel of the measurement point through the server and informs the responsible personnel of the measurement point of the simulation result of the measurement point of the given key measurement point of troubleshooting.
As a preferable technical measure:
in the first step, the metering of the electric energy comprises calculating the direct current power, which comprises an effective valueMethod or mean value method or instantaneous value method; wherein, the sampling time is T, and the sampling start time is T0The voltage sampling instantaneous value is u (t), the current sampling instantaneous value is i (t), and the expressions of the three calculation schemes are respectively:
as a preferable technical measure:
in the second step, data reading adopts an open form, and expansion and new equipment addition are supported;
the data storage is written by java language, and the https protocol and the JSON or XML form are used for data transmission.
As a preferable technical measure:
in the third step, a modeling fitting method is adopted to carry out flicker analysis and ripple analysis;
the voltage expression of the voltage signal in T time is as follows:
the target is fit to estimate the parameters during T time
And (3) if the absolute value of the difference between the estimation expression (4) and the sampling voltage is as small as possible, fitting the target expression as follows:
wherein u (t) is a voltage instantaneous value obtained by collection; Δ u is the voltage flicker amplitude during time T; u shapemIs the ripple amplitude; omega is ripple frequency;
is the ripple phase.
As a preferable technical measure:
searching the fitting target expression by adopting a simulated annealing algorithm in a given estimation parameter searching range;
the searching steps are as follows:
step 1: number of initialization iterations k, temperature parameter CpAccuracy epsilon, cooling coefficient alpha, randomly generating a set of estimation parameters pi；
Step 2: initial feasible solution piCalculating a fitting objective function value J (p)i)；
And step 3: judgment of equilibrium Condition J (p)i) If the epsilon is less than epsilon, turning to a step 6 if the epsilon is true, or turning to a step 4-5 if the epsilon is not true;
and 4, step 4: randomly generating a set of estimated parameters p in the neighborhood of the current solutionjCalculating its fitting objective function value J (p)j)；
And 5: performing an acceptance criterion, if J (p)j)≤J(pi) Then receive pjReturning to the step 2 for feasible solution; otherwise, judging the acceptance probability
If true, accept pjIf the solution is feasible, returning to the step 2, otherwise, directly returning to the step 2;
step 6: if the iteration times are reached, stopping the iteration; reduction of temperature, C'p＝αCpGo back to step 2.
Compared with the prior art, the invention has the following beneficial effects:
according to the method, through continuous exploration and test, for a plurality of alternative metering points, a factor set, a comment set, a weight set and a judgment result matrix are constructed by using a fuzzy comprehensive evaluation model, and the final comment results of all schemes are compared to select a final metering point configuration scheme, so that the influence of subjective factors can be effectively reduced, the metering points can be selected more scientifically, reasonably and accurately, and the method is favorable for popularization.
Drawings
Fig. 1 is a flow chart of a medium-low voltage direct current metering point selection system of the invention.
FIG. 2 is a fuzzy comprehensive evaluation model process of the medium and low voltage DC metering point selection system of the present invention.
Fig. 3 is a schematic diagram of a metering point site of a two-stage photovoltaic grid-connected system with a direct-current load.
Fig. 4 is a schematic diagram of the metering point addressing applied to the double-ended flexible direct-current power transmission system.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
On the contrary, the invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
As shown in fig. 1-2, the selection method of the medium and low voltage direct current metering point based on the fuzzy evaluation model,
evaluating the plurality of candidate metering points through a fuzzy comprehensive evaluation model to select a proper metering point;
which comprises the following steps:
firstly, constructing a factor set U; the set of factors U includes "accuracy U1"," economy u2", and" feasibility u3", i.e. U ═ U1，u2，u3}；
Secondly, constructing a comment set V;
the comment set V includes "good V1"," preferably v2"," acceptable v3"and" unacceptable v4", i.e. V ═ V1，v2，v3，v4}；
Thirdly, constructing a weight set A;
weight set a ═ a1，a2，a3Expressing the proportion of each factor in the system design decision;
fourthly, according to the membership degree of the factor set to the comment set, a judgment decision matrix is given to each metering point
Row vector [ r ] of the evaluation decision matrixi1，ri2，ri3，ri4]Representing the degree of membership of the factor in the set of comments;
it should be noted that the sum of the row vectors of the evaluation matrix is 1, i.e. the sum of the row vectors of the evaluation matrix is 1
Fifthly, constructing a judgment result matrix B as A multiplied by R to obtain a judgment result matrix B as B1，b2，b3，b4]；
Four elements in the evaluation result matrix respectively correspond to the membership degree of the scheme in the evaluation set, and the maximum value B is taken as max B to serve as the final evaluation result of the scheme;
sixthly, selecting a final metering point configuration scheme by comparing final comment results of all schemes;
and when the comment results are the same, selecting the person with the highest membership degree.
According to the method, through continuous exploration and test, for a plurality of alternative metering points, a factor set, a comment set, a weight set and a judgment result matrix are constructed by using a fuzzy comprehensive evaluation model, and the final comment results of all schemes are compared to select a final metering point configuration scheme, so that the influence of subjective factors can be effectively reduced, the metering points can be selected more scientifically, reasonably and accurately, and the method is favorable for popularization.
The invention relates to an alternative metering point selection embodiment:
the first step, selecting a plurality of alternative metering points, wherein the metering points are selected mainly according to national standards GB/T33708-2017 and industry standards DL/T1484-2015 and DL/T448-2016, and each metering point is ensured to meet basic requirements; and generating a plurality of metering point configuration combination schemes as an alternative.
The method is based on a network topology structure of the direct-current power distribution network, considers the symmetry of the direct-current power distribution network and the distributed power grid-connected structure, starts from national standards and industrial standards, and applies a fuzzy comprehensive evaluation model. The accuracy, the economy and the feasibility of the setting of the metering points are comprehensively considered, and the optimal scheme can be screened out from the potential metering points which accord with the national standard and the industrial standard.
As shown in fig. 3, the present invention is applied to embodiment 1 of a two-stage photovoltaic grid-connected system with a dc load.
In example 1, according to the national standard and the industrial standard, 3 potential metering points are selected in advance, and three metering point combination schemes are given:
| |
1+2+3 |
| Scheme 2 | 1+2 |
| |
3 |
In the scheme 1, the metering point is completely set, the actual inflow/outflow electric energy of each device is fully considered, the influence of line loss on metering is minimum, and therefore the accuracy is highest. But at the same time, a plurality of electric meters are installed, and the system cost is increased. In the installation feasibility, when the user side is involved, factors such as whether residents agree to power failure installation equipment or home construction and the like are often involved, and the installation difficulty is high. In the scheme 3, only power exchange between the grid-connected system and the main grid is considered, and the electricity consumption situation of the residential load side cannot be fully reflected.
And configuring an evaluation decision matrix and a weight set according to an empirical method. The three schemes evaluate the decision matrix and weight set as follows:
scheme 1:
scheme 2:
scheme 3:
weight set A ═ 0.30.40.3-
The final evaluation result is:
scheme 1: b is1＝|0.35 0.19 0.39 0.07|
Scheme 2: b is2＝|0.16 0.47 0.30 0.07|
Scheme 3: b is3＝|0.22 0.42 0.33 0.06|
As can be seen from the results, the evaluation results of case 2 and 3 are similar, but case 2 has a greater degree of membership to "better". Scheme 2 was therefore chosen.
As shown in fig. 4, the present invention is applied to embodiment 2 of the double-ended flexible dc power transmission system:
firstly, according to the national standard and the industry standard, 10 potential metering points are selected for site selection in advance, and the specific site selection mode is B1-B10 in FIG. 4. Four combinations of solutions are given simultaneously:
in the embodiment, the influence factors such as the accuracy of electric energy measurement and the difficulty degree of meter installation are more. Because of the ac-dc conversion involved, the harmonics present in the system have a large impact on the metering accuracy. Through simulation analysis, harmonics at the potential metering points B4/B7 on the direct current side and the potential metering points B3/B8 on the alternating current side are serious. In addition, voltage sag also affects errors of measurement results, and whether space remains at a selected site or not and the difficulty of an installation process caused by voltage level are considered in the difficulty of installing the electric energy meter. In the price factor, the price of the metering equipment needed by the metering site selection points B2, B3, B8 and B9 before and after the reactor is higher. According to the principle, each scheme evaluation decision matrix is generated, and the weight set is the same as that in the embodiment 1.
Scheme 1:
scheme 2:
scheme 3:
scheme 4:
the final evaluation result matrix is:
as can be seen from the results, the evaluation results for case 3 and 4 are similar, but case 3 has a greater degree of membership to "good". Scheme 3 was therefore chosen.
The embodiment of the metering method for the selected metering point comprises the following steps:
the metering method of the medium-low voltage direct current metering point comprises the following steps:
collecting system operation information and metering electric energy;
reading the collected metering data and equipment alarm information, and storing the data;
the data reading adopts an open form, and supports expansion and new equipment addition;
the data storage is written by java language, and the https protocol and the JSON or XML form are used for data transmission.
Processing the acquired data, analyzing the running state of the system and calculating the electric charge;
data processing includes, but is not limited to: flicker analysis, ripple analysis, tip, peak, valley and level analysis and system direct current power flow analysis; issuing a system operation instruction according to the data processing result, and transmitting the instruction to the control station through the server, thereby realizing electric energy management;
simulating the running state of the system, and giving a measurement result reference range of the key measurement point as a measurement result calibration standard; if the simulation result is larger than the reference range and no alarm information exists at the moment, sending information to a person in charge of the metering point where the simulation result is located, and informing the person to go to the position where the metering point is located to troubleshoot faults.
The invention measures the electric energy by acquiring the actual operation information of the system; meanwhile, the electric energy can be effectively managed and the metering result can be corrected according to the collected information, and the scheme is scientific, reasonable and accurate; the method can meet the requirements of scientific measurement of medium and low voltage direct current transmission systems of power grid companies and users.
Further, the simulation process in the fourth step specifically includes the following steps:
s1, logging in the system by a terminal manager;
s2, after logging in, the terminal manager inputs weather forecast conditions, load forecast conditions, direct current converter station control modes, system direct current bus voltage standard values and system direct current bus power standard values into the system;
s3, after data entry, running simulation to obtain a simulation result;
in the specific simulation process, a simscape power system toolbox in matlab/simulink software can be used for modeling according to the topological structure of the power distribution network through an existing component library in the toolbox, and then data in S2 is input to obtain a simulation result;
s4, comparing the simulation result with the measurement result of the given key measurement point;
if the simulation result is greatly different from the measurement result of the given key measurement point and no alarm information exists at the moment, the electric energy management layer sends information to the responsible personnel of the measurement point through the server and informs the responsible personnel of the measurement point of the simulation result of the measurement point of the given key measurement point of troubleshooting.
The invention relates to a specific embodiment of electric energy metering:
in the first step, the measurement of the electric energy comprises the calculation of direct current power, which comprises an effective value method, an average value method or an instantaneous value method; wherein, the sampling time is T, and the sampling start time is T0The voltage sampling instantaneous value is u (t), the current sampling instantaneous value is i (t), and the expressions of the three calculation schemes are respectively:
an embodiment of the data processing of the present invention:
carrying out flicker analysis and ripple analysis by adopting a modeling fitting method;
the voltage expression of the voltage signal in T time is as follows:
the target is fit to estimate the parameters during T time
And (3) if the absolute value of the difference between the estimation expression (4) and the sampling voltage is as small as possible, fitting the target expression as follows:
wherein u (t) is a voltage instantaneous value obtained by collection; Δ u is the voltage flicker amplitude during time T; u shapemIs the ripple amplitude; omega is ripple frequency;
is the ripple phase.
Searching the fitting target expression by adopting a simulated annealing algorithm in a given estimation parameter searching range;
the searching steps are as follows:
step 1: number of initialization iterations k, temperature parameter CpAccuracy epsilon, cooling coefficient alpha, randomly generating a set of estimation parameters pi；
Step 2: initial feasible solution piCalculating a fitting objective function value J (p)i)；
And step 3: judgment of equilibrium Condition J (p)i) If the epsilon is less than epsilon, turning to a step 6 if the epsilon is true, or turning to a step 4-5 if the epsilon is not true;
and 4, step 4: randomly generating a set of estimated parameters p in the neighborhood of the current solutionjCalculating its fitting objective function value J (p)j)；
And 5: performing an acceptance criterion, if J (p)j)≤J(pi) Then receive pjReturning to the step 2 for feasible solution; otherwise, judging the acceptance probability
If true, accept pjIf the solution is feasible, returning to the step 2, otherwise, directly returning to the step 2;
step 6: if the iteration times are reached, stopping the iteration; reduction of temperature, C'p＝αCpGo back to step 2.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (10)
1. A middle and low voltage direct current metering point selection method based on a fuzzy evaluation model is characterized in that,
evaluating the plurality of candidate metering points through a fuzzy comprehensive evaluation model to select a proper metering point;
which comprises the following steps:
firstly, constructing a factor set U; the set of factors U includes "accuracy U1"," economy u2", and" feasibility u3", i.e. U ═ U1，u2，u3}；
Secondly, constructing a comment set V;
the above-mentionedComment set V includes "good V1"," preferably v2"," acceptable v3"and" unacceptable v4", i.e. V ═ V1，v2，v3，v4}；
Thirdly, constructing a weight set A;
weight set a ═ a1，a2，a3Expressing the proportion of each factor in the system design decision;
fourthly, according to the membership degree of the factor set to the comment set, a judgment decision matrix R ═ R is given to each metering pointij|3×4；
Row vector [ r ] of the evaluation decision matrixi1，ri2，ri3，ri4]Representing the degree of membership of the factor in the set of comments.
Fifthly, constructing a judgment result matrix B as A multiplied by R to obtain a judgment result matrix B as B1，b2，b3，b4]；
Four elements in the evaluation result matrix respectively correspond to the membership degree of the scheme in the evaluation set, and the maximum value B is taken as max B to serve as the final evaluation result of the scheme;
sixthly, selecting a final metering point configuration scheme by comparing final comment results of all schemes;
and when the comment results are the same, selecting the person with the highest membership degree.
2. The method for selecting the middle and low voltage direct current metering point based on the fuzzy evaluation model as claimed in claim 1,
the first step, selecting a plurality of alternative metering points, wherein the metering points are selected mainly according to national standards GB/T33708-2017 and industry standards DL/T1484-2015 and DL/T448-2016, and each metering point is ensured to meet basic requirements; and generating a plurality of metering point configuration combination schemes as an alternative.
3. The method for selecting the middle and low voltage direct current metering point based on the fuzzy evaluation model as claimed in claim 1,
thirdly, adjusting the weight set data according to actual requirements;
when the overall design of the system is more biased to economy, the value of a2 is larger;
the sum of the elements of the weight set is 1, i.e.
4. The method for selecting the middle and low voltage direct current metering point based on the fuzzy evaluation model as claimed in claim 1,
and in the fourth step, the membership degree evaluation method comprises a statistical method and a membership function method.
5. The method for selecting the middle and low voltage direct current metering point based on the fuzzy evaluation model as claimed in claim 1,
for a two-stage photovoltaic grid-connected system with a direct-current load, 3 potential metering points are selected for site selection according to national standards and industrial standards, and three metering point combination schemes are provided:
in the first scheme, three metering points are selected completely;
selecting two metering points;
and a third scheme, selecting a metering point:
configuring an evaluation decision matrix and a weight set;
the three schemes evaluate the decision matrix and weight set as follows:
scheme 1:
scheme 2:
scheme 3:
weight set A ═ 0.30.40.3-
The final evaluation result is:
scheme 1: b is1＝|0.35 0.19 0.39 0.07|
Scheme 2: b is2＝|0.16 0.47 0.30 0.07|
Scheme 3: b is3＝|0.22 0.42 0.33 0.06|。
6. The method for selecting the middle and low voltage DC metering point based on the fuzzy evaluation model according to any one of claims 1 to 5,
the method for metering the medium-low voltage direct current metering points comprises the following steps:
collecting system operation information and metering electric energy;
reading the collected metering data and equipment alarm information, and storing the data;
processing the acquired data, analyzing the running state of the system and calculating the electric charge;
data processing includes, but is not limited to: flicker analysis, ripple analysis, tip, peak, valley and level analysis and system direct current power flow analysis; issuing a system operation instruction according to the data processing result, and transmitting the instruction to the control station through the server, thereby realizing electric energy management;
simulating the running state of the system, and giving a measurement result reference range of the key measurement point as a measurement result calibration standard; if the simulation result is larger than the reference range and no alarm information exists at the moment, sending information to a person in charge of the metering point where the simulation result is located, and informing the person to go to the position where the metering point is located to troubleshoot faults.
7. The method for selecting the middle and low voltage DC metering point based on the fuzzy evaluation model as claimed in claim 6,
in the first step, the measurement of the electric energy comprises the calculation of direct current power, which comprises an effective value method, an average value method or an instantaneous value method; wherein the sampling time isT, the sampling start time is T0The voltage sampling instantaneous value is u (t), the current sampling instantaneous value is i (t), and the expressions of the three calculation schemes are respectively:
8. the method for selecting the middle and low voltage DC metering point based on the fuzzy evaluation model as claimed in claim 7,
in the second step, data reading adopts an open form, and expansion and new equipment addition are supported;
the data storage is written by java language, and the https protocol and the JSON or XML form are used for data transmission.
9. The method for selecting the middle and low voltage DC metering point based on the fuzzy evaluation model as claimed in claim 8,
in the third step, a modeling fitting method is adopted to carry out flicker analysis and ripple analysis;
the voltage expression of the voltage signal in T time is as follows:
the target is fit to estimate the parameters during T time
Make the estimation tableIf the absolute value of the difference between the expression (4) and the sampling voltage is as small as possible, the fitting target expression is as follows:
wherein u (t) is a voltage instantaneous value obtained by collection; Δ u is the voltage flicker amplitude during time T; u shapemIs the ripple amplitude; omega is ripple frequency;
is the ripple phase.
10. The method for selecting the middle and low voltage DC metering point based on the fuzzy evaluation model as claimed in claim 9,
searching the fitting target expression by adopting a simulated annealing algorithm in a given estimation parameter searching range;
the searching steps are as follows:
step 1: number of initialization iterations k, temperature parameter CpAccuracy epsilon, cooling coefficient alpha, randomly generating a set of estimation parameters pi；
Step 2: initial feasible solution piCalculating a fitting objective function value J (p)i)；
And step 3: judgment of equilibrium Condition J (p)i) If the epsilon is less than epsilon, turning to a step 6 if the epsilon is true, or turning to a step 4-5 if the epsilon is not true;
and 4, step 4: randomly generating a set of estimated parameters p in the neighborhood of the current solutionjCalculating its fitting objective function value J (p)j)；
And 5: performing an acceptance criterion, if J (p)j)≤J(pi) Then receive pjReturning to the step 2 for feasible solution; otherwise, judging the acceptance probability
If true, accept pjIf the solution is feasible, returning to the step 2, otherwise, directly returning to the step 2;
step 6: if the iteration times are reached, stopping the iteration; lowering the temperature, C-p＝αCpGo back to step 2.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001099876A (en) * | 1999-09-29 | 2001-04-13 | Yokogawa Electric Corp | Effective current measuring device |
| CN201804097U (en) * | 2010-07-06 | 2011-04-20 | 张德军 | High voltage electric energy metering device with on-line checking and testing standard |
| JP2012220330A (en) * | 2011-04-08 | 2012-11-12 | Panasonic Corp | Distributed power generating system |
| CN103454491A (en) * | 2013-08-15 | 2013-12-18 | 江苏科技大学 | Intelligent electric meter and power quality detection method |
| CN104991223A (en) * | 2015-07-27 | 2015-10-21 | 国网重庆市电力公司电力科学研究院 | Watt-hour meter state assessment index selection and quantization method |
| CN106339567A (en) * | 2016-11-01 | 2017-01-18 | 中国电力科学研究院 | Wind power plant flickering transfer calculating method based on system impedance and wind power plant flickering transfer calculating device based on system impedance |
| CN109387804A (en) * | 2017-08-09 | 2019-02-26 | 国网浙江省电力公司电力科学研究院 | The soft lineal statistic method of one kind, metering device accuracy checking method and system |
| CN110046797A (en) * | 2019-01-04 | 2019-07-23 | 国网浙江省电力有限公司 | Measuring equipment running quality appraisal procedure based on CRITIC and ideal point method |
| CN110826228A (en) * | 2019-11-07 | 2020-02-21 | 国网四川省电力公司电力科学研究院 | Regional power grid operation quality limit evaluation method |
| CN112103956A (en) * | 2020-09-18 | 2020-12-18 | 福州大学 | Distribution network state estimation method based on intelligent electric meter dynamic measurement point |
-
2021
- 2021-01-20 CN CN202110073353.4A patent/CN112818523B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001099876A (en) * | 1999-09-29 | 2001-04-13 | Yokogawa Electric Corp | Effective current measuring device |
| CN201804097U (en) * | 2010-07-06 | 2011-04-20 | 张德军 | High voltage electric energy metering device with on-line checking and testing standard |
| JP2012220330A (en) * | 2011-04-08 | 2012-11-12 | Panasonic Corp | Distributed power generating system |
| CN103454491A (en) * | 2013-08-15 | 2013-12-18 | 江苏科技大学 | Intelligent electric meter and power quality detection method |
| CN104991223A (en) * | 2015-07-27 | 2015-10-21 | 国网重庆市电力公司电力科学研究院 | Watt-hour meter state assessment index selection and quantization method |
| CN106339567A (en) * | 2016-11-01 | 2017-01-18 | 中国电力科学研究院 | Wind power plant flickering transfer calculating method based on system impedance and wind power plant flickering transfer calculating device based on system impedance |
| CN109387804A (en) * | 2017-08-09 | 2019-02-26 | 国网浙江省电力公司电力科学研究院 | The soft lineal statistic method of one kind, metering device accuracy checking method and system |
| CN110046797A (en) * | 2019-01-04 | 2019-07-23 | 国网浙江省电力有限公司 | Measuring equipment running quality appraisal procedure based on CRITIC and ideal point method |
| CN110826228A (en) * | 2019-11-07 | 2020-02-21 | 国网四川省电力公司电力科学研究院 | Regional power grid operation quality limit evaluation method |
| CN112103956A (en) * | 2020-09-18 | 2020-12-18 | 福州大学 | Distribution network state estimation method based on intelligent electric meter dynamic measurement point |
Non-Patent Citations (10)
| Title |
|---|
| 丁业松: "石化企业低压电力监控和全厂电量管理***设计与开发", 中国优秀博硕士学位论文全文数据库 * |
| 吴婷;杨剑锋;苗青;石青;: "APF直流侧纹波电压分析及新PI控制策略研究", 电力电子技术, no. 05 * |
| 崔高颖;周玉;郑爱霞;易永仙;潘超;: "基于熵权的计量技术监督模糊综合评价方法", 江苏电机工程, no. 05, pages 1 - 5 * |
| 张春娜;李富平;郎红东;: "唐山市南湖公园水环境质量的模糊综合评价", 安徽农业科学, no. 34 * |
| 曾君;徐冬冬;郭华芳;李晨迪;刘俊峰;: "面向可再生能源的微电网电能质量特点分析与综合评价方法研究", 电力***保护与控制, no. 19, pages 1 - 7 * |
| 朱晓岭;高云辉;谢小英;焦晋荣;贾清泉;: "基于相关原子库的直流配电网电能质量扰动检测方法", 燕山大学学报, no. 05 * |
| 杨啸宇;: "简析电能质量在线监测***的应用", 企业导报, no. 21 * |
| 莫玉平;: "论装表接电在降损过程中的重要性", 低碳世界, no. 15, pages 1 - 2 * |
| 陆春光 等: "基于模糊聚类算法的电能计量箱接插件性能评估方法", 电测与仪表 * |
| 陈炜豪;林志贤;王星光;: "电压波动和闪变对整流桥后电解电容器的影响", 电子技术应用, no. 11 * |
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